A tumour is an abnormal growth made up of cells that push the surrounding normal tissue out of way as it grows. Tumour does not mean the same thing as cancer. A tumour can be either non-cancerous (benign) or a cancer (malignant).
One of the most important roles that a pathologist plays in your medical medical care is determining whether a tumour is non-cancerous or cancerous. By examining tissue from the tumour under the microscope, pathologists can reliably tell the difference between non-cancerous and cancerous tumours in most circumstances.
The behavior of a tumour depends on its location in the body, the cells that make up the tumour, and whether the tumour is non-cancerous or cancerous.
Some non-cancerous tumours can grow to become very large. However, most non-cancerous tumours are unable to spread to other parts of the body. In contrast, cancerous tumours have the ability to spread into surrounding tissues or other parts of the body.
The movement of tumour cells into the surrounding normal tissue is called invasion.
A metastasis is a group of tumour cells that have spread to a different part of the body. Lymph nodes are a common site for metastatic disease.